It is now well established that angiogenesis, which involves the formation of new blood vessels from preexisting endothelium, is implicated in the pathogenesis of a variety of disorders. These include solid tumors and metastasis, atherosclerosis, retrolental fibroplasia, hemangiomas, chronic inflammation, intraocular neovascular syndromes such as proliferative retinopathies, e.g., diabetic retinopathy, age-related macular degeneration (AMD), neovascular glaucoma, immune rejection of transplanted corneal tissue and other tissues, rheumatoid arthritis, and psoriasis. Folkman et al., J. Biol. Chem., 267: 10931-10934 (1992); Klagsbrun et al., Annu Rev. Physiol., 53: 217-239 (1991); and Garner A., “Vascular diseases”, In: Pathobiology of Ocular Disease. A Dynamic Approach, Garner A., Klintworth G K, eds., 2nd Edition (Marcel Dekker, NY, 1994), pp 1625-1710.
In the case of tumor growth, angiogenesis appears to be crucial for the transition from hyperplasia to neoplasia, and for providing nourishment for the growth and metastasis of the tumor. Folkman et al., Nature, 339: 58 (1989). The neovascularization allows the tumor cells to acquire a growth advantage and proliferative autonomy compared to normal cells. A tumor usually begins as a single aberrant cell which can proliferate only to a size of a few cubic millimeters due to the distance from available capillary beds, and it can stay ‘dormant’ without further growth and dissemination for a long period of time. Some tumor cells then switch to the angiogenic phenotype to activate endothelial cells, which proliferate and mature into new capillary blood vessels. These newly formed blood vessels not only allow for continued growth of the primary tumor, but also for the dissemination and recolonization of metastatic tumor cells. Accordingly, a correlation has been observed between density of microvessels in tumor sections and patient survival in breast cancer as well as in several other tumors. Weidner et al., N. Engl. J. Med, 324: 1-6 (1991); Horak et al., Lancet, 340: 1120-1124 (1992); Macchiarini et al., Lancet, 340: 145-146 (1992). The precise mechanisms that control the angiogenic switch is not well understood, but it is believed that neovascularization of tumor mass results from the net balance of a multitude of angiogenesis stimulators and inhibitors (Folkman, 1995, Nat Med 1(1):27-31).
The process of vascular development is tightly regulated. To date, a significant number of molecules, mostly secreted factors produced by surrounding cells, have been shown to regulate EC differentiation, proliferation, migration and coalescence into cord-like structures. For example, vascular endothelial growth factor (VEGF) has been identified as the key factor involved in stimulating angiogenesis and in inducing vascular permeability. Ferrara et al., Endocr. Rev., 18: 4-25 (1997). The finding that the loss of even a single VEGF allele results in embryonic lethality points to an irreplaceable role played by this factor in the development and differentiation of the vascular system. Furthermore, VEGF has been shown to be a key mediator of neovascularization associated with tumors and intraocular disorders. Ferrara et al., Endocr. Rev., supra. The VEGF mRNA is overexpressed by the majority of human tumors examined. Berkman et al., J. Clin. Invest., 91: 153-159 (1993); Brown et al., Human Pathol., 26: 86-91 (1995); Brown et al., Cancer Res., 53: 4727-4735 (1993); Mattern et al., Brit. J. Cancer, 73: 931-934 (1996); Dvorak et al., Am. J. Pathol., 146: 1029-1039 (1995).
Bv8 has been shown to induce proliferation, survival and migration of adrenal cortical capillary endothelial cells (LeCouter, J. et al., Proc Natl Acad Sci USA 100, 2685-2690 (2003)). Bv8 and EG-VEGF are two highly related secreted proteins, also referred to as prokineticin-1 and -2, which structurally belong to a larger class of peptides defined by a five disulphide bridge motif called a colipase fold (DeCouter, J. et al., Nature 420, 860-867 (2002); LeCouter, J. et al., Proc Natl Acad Sci USA 100, 2685-2690 (2003); Li, M. et al., Mol Pharmacol 59, 692-698 (2001)). Bv8 was initially identified as a secreted protein from the skin of the frog Bombina variegate (Mollay, C. et al., Eur J Pharmacol 374, 189-196 (1999)). The cloning and expression of Bv8 are described in WO 03/020892 published on Mar. 13, 2003. Bv8 and EG-VEGF bind two highly related G-protein coupled receptors (GPCR), EG-VEGF/PKR-1 (R1) and EG-VEGF/PKR-2 (R2) (Masuda, Y et al., Biochem Biophys Res Commun 293, 496-402 (2002); Lin, D. C. et al., J Biol Chem 277, 19276-19280 (2002)). EG-VEGF and Bv8 were characterized as mitogens selective for specific endothelial cell types (LeCouter, J. et al., Nature 412(6850):877-84 (2001) and LeCouter, J. et al., Proc Natl Acad Sci USA 100, 2685-2690 (2003)). Other activities have been ascribed to this family, including nociception (Mollay, C. et al., supra), gastrointestinal tract motility (Li, M. et al., supra), regulation of circadian locomotor rhythm (Cheng, M. Y., et al., Nature 417, 405-410 (2002)) and olfactory bulb neurogenesis (Matsumoto, S., et al., Proc Natl Acad Sci USA 103, 4140-4145 (2006)). Furthermore, Bv8 stimulated production of granulocytic and monocytic colonies in vitro (LeCouter, J. et al., (2003), supra; Dorsch, M. et al., J. Leukoc Biol 78(2), 426-34 (2005)). Bv8 has been characterized as a chemoattractact for macrophages (LeCouter et al., Proc Natl Acad Sci USA 101, 16813-16919 (2004)).
In view of the role of angiogenesis in many diseases and disorders, it is desirable to have a means of reducing or inhibiting one or more of the biological effects causing these processes. All references cited herein, including patent applications and publications, are incorporated by reference in their entirety.